Field of the Invention
The present invention relates to a radiographic image capturing apparatus and a radiographic image capturing system, particularly to a radiographic image capturing apparatus that can capture serial images, such as moving images, of a subject and a radiographic image capturing system including the radiographic image capturing apparatus.
Description of Related Art
Radiographic image capturing apparatuses using flat panel detectors (FPDs) are well known. Traditional radiographic image capturing apparatuses have integrated supports and are used for particular purposes. In recent years, portable radiographic image capturing apparatuses including radiation detectors in housing so as to be portable have been developed and used in practice.
With such a radiographic image capturing apparatus, a series of radiographic image capturing including the successive irradiation of a subject with radiation are conducted for producing moving images or other images in some cases. The series of radiographic image capturing involves a sequence of readouts of the resulting image data D to capture radiographic images of frames for moving images or other images. In particular, the process alternates between the irradiation of a subject with radiation from a radiation source 52 of a radiation generator 55 (see FIG. 4, for example) to a radiographic image capturing apparatus, and the readout of the image data D from radiation detectors 7. Thus, the image data Dare generated through a series of radiographic image capturing. A radiographic image is generated from the image data D produced by each radiographic image capturing, resulting in the generation of moving images or other images.
For instance, if the radiation generator 55 and the radiographic image capturing apparatus are made by the same manufacturer, an interface can be established between them. For instance, a signal is transmitted to the radiation generator 55 when the radiographic image capturing apparatus becomes ready to be irradiated with radiation, and the radiation generator 55 emits radiation upon the reception of the signal, so that the process properly alternates between the irradiation with radiation from the radiation generator 55 and the readout of the image data D by the radiographic image capturing apparatus to capture moving images or other images.
If the manufacturers of the radiation generator 55 and the radiographic image capturing apparatus are different, the establishment of an interface therebetween is not always readily achievable or may be unachievable. In such a case, the radiographic image capturing apparatus cannot sense the timing of the emission of radiation from the radiation generator 55. Such a trouble in coordination between the radiation generator 55 and the radiographic image capturing apparatus may cause an overlap between the timing of the readout of the image data D in the radiographic image capturing apparatus and the timing of the irradiation with radiation from the radiation generator 55.
For instance, if the radiation generator 55 starts the next irradiation of radiation while the radiographic image capturing apparatus reads out the image data D based on the electric charge generated by the preceding irradiation of radiation in each radiation detector 7, the image data D generated by the preceding radiographic image capturing is not accurately read from each radiation detector 7 due to the electric charge generated by the following irradiation of radiation in each radiation detector 7. Similarly, if the readout of the image data D starts too early, and the readout of the image data D starts during the irradiation, the image data D cannot be correctly readout.
Accordingly, a minimum requirement for radiographic capturing for moving images or other images without establishment of an interface between the radiation generator 55 and the radiographic image capturing apparatus is to avoid an overlap between the timing of the readout of the image data D in the radiographic image capturing apparatus and the timing of the irradiation with radiation from the radiation generator 55 to capture moving images or other images.